MDM vs Time-Based Coding for Hospital E/M (99221‑99223): Surviving 2026 Payer Audits on Prolonged and Split/Shared Documentation
The 2026 Audit Trap: When Payers See "Time" and Smell Money
Every hospitalist team has seen it: a Medicare Advantage audit from UnitedHealthcare or Aetna slicing down your 99223 to a 99221 with no reason beyond “time documentation insufficient.” You look back at the note, 35 minutes with a septic patient, critical care managed by another team, multiple problems addressed, and yet UHC’s portal flags it for “MDM-level substantiation.” The carrier switches your time-based code to MDM logic and claws back $86 per encounter. Over a quarter, that’s $40,000 gone for one internal medicine group.
This isn’t rare anymore. RACmonitor has shown that Medicare Advantage plans are running algorithms designed to downcode any claim that leans on time documentation. They say it’s about “data integrity.” Let’s be honest, it’s cost control, disguised as compliance. And if you roll over and take the lower payment, you could be walking yourself straight into False Claims Act risk. The OIG has made clear in 2025-2026 reviews that accepting downcoded MA claims can be interpreted as admitting the original level wasn’t valid. That’s the trap.
MDM vs Time: Why It Fell Apart for Inpatient Coders
After the E/M overhaul baked into the 2025 MPFS, inpatient and observation admissions (CPT 99221-99223) can be selected by time or MDM. On paper, time was supposed to cut through the gray area. In practice? It turned into an audit magnet. Aetna and Cigna now want proof of every minute: what you did, how long it took, and why it qualifies. “Total time 45 minutes” without detail is basically an invitation to downcode. Write “discussed plan with family” but don’t specify it’s over half the total time? Expect a denial.
CMS still defines total time as both direct and indirect work, but payers are slicing that definition razor-thin. “Care coordination” now needs specifics, what coordination, with whom, about what. Anthem reviewers have been removing those minutes and resetting 99223s to 99222s without blinking. The difference adds up fast.
Here’s where it really turns ugly. When both time and MDM are documented, auditors pick whichever supports the lower code. Cigna even spelled it out in Q1 2026 letters: “selection by most conservative interpretive standard.” The only defense is being explicit in your note, state your method. “Level selected based on total time 72 minutes.” Or “Level selected based on high-complexity MDM.” If you don’t, the payer decides for you, and you already know whose side they’ll take.
Prolonged + Split/Shared: The Quiet Revenue Drain
Prolonged care (CPT +99418 for facility visits) looked like easy margin in the 2025 tables. It isn’t anymore. Anthem, Aetna, and UHC now want start and stop times, no rounding, no guessing. “Total 78 minutes with 8 beyond threshold.” Anything else gets recoded as a basic 99223 with CO-151 slapped on the remit. That’s typically a $63 hit per case, and most hospitals never appeal because the effort outweighs the return.
Then there’s split/shared. CMS doubled down in the 2026 rule, whoever performs the substantive portion (MDM or >50% total time) bills the encounter. But people are still co-signing notes like it’s 2019. If an NP spends 42 minutes and the MD adds one paragraph, that’s the NP’s visit. UHC and Humana auditors are comparing EHR timestamps against logins to catch that mismatch, and the recoveries are staggering.
I’ve watched one hospitalist group in Ohio lose $380,000 in 18 months over simple split/shared mismatches. Prolonged add-ons denied automatically because the substantive provider field was incomplete. Fixes take clean design, EHR templates that force time splits and make the total undeniable. Don’t wait for compliance to rescue it; the payer bots move too fast.
Monday Morning Fix: Notes That Don’t Collapse in an Audit
The only way through this 2026 mess is clarity. Pick one method in every hospital E/M note, time or MDM, and own it. If by time, write it like evidence: “Total 74 minutes, labs (10), exam (15), counseling (14), coordination (35). Time-based code selection.” If by MDM, show your work: what made it high risk, which data you reviewed, who you coordinated with. Mixing them casually is asking for recode and repayment.
Track the payers that keep downcoding. Build a workflow that tags every “level reduced” remit for same-day appeal using the note you already have. CMS is poking at payer coding algorithms in 2026, see the latest Federal Register posts about HCPCS transparency, but you won’t benefit if you never push back. Hospitals that keep cashing downcoded checks aren’t victims anymore. They’re targets.
So, fix the templates, sure, but more than that, fix how your team thinks about documentation. Name your method, back it with time data that holds up, and fight every downgrade that isn’t justified. Look, MA payers built this audit loop. You don’t have to accept living in it.